Ludington Building

The city's earliest-surviving, steel-frame building, a type of construction that changed modern architecture. It represents one of the high points of its designer, William Le Baron Jenney, who is widely considered to be the "father of the skyscraper." As one of the first structures to be completely clad in terra cotta, it also marks an important step in Chicago's leadership in the development of the architectural terra cotta industry. Its purity of form and delicacy of ornamental detail mark it as one of the most significant visual landmarks of the South Loop. It was built by Mary Ludington to house the American Book Company.